As Napoleon's France surrendered at the battle of Waterloo, the Final Act of the Congress of Vienna of 1815 was redrawing the political map of Europe. The Congress of Vienna created what is known as the balance-of-power system, which despite imminent crisis would persist until the start of World War I in 1914. For a more detailed information on the Battle of Waterloo from a British perspective, read this BBC article.

From its unification up until World War I, the German Empire gradually became the main power in continental Europe. When Otto von Bismarck stepped down in 1888, Germany replaced its practical realpolitik under the auspices of Emperor Wilhelm II with a more aggressive weltpolitik. This new policy contributed to a widespread international crisis that would lead to World War I.

In 1867, following the 1866 defeat in the Austro-Prussian war, the Emperor Franz Joseph of Austria signed the Austro-Hungarian compromise creating the dual monarchy of Austria-Hungary. Frustrated in its hope to unify the German States by Prussia's victory; the Austro-Hugarian Emperor hence focused his attention on the Balkans.

Read more on this site about the organizational history of the land forces of the Austro-Hungarian monarchy prior to the outbreak of the Great War until the collapse of the monarchy in 1918. Photographs and biographies are available in addition to this film footage of Franz Josef taken before the outbreak of the First World War.

In 1914, responding to the Austro-Hungarian declaration of war on Serbia, the Russian Empire ordered partial mobilization, which in turn involved its allies of the Triple Entente, France and the British Empire. Russia would leave the war in 1918 following Lenin's accession to power after the October Revolution.

Lasting from 1300 to 1923, the Ottoman Empire at its peak encompassed most of Eastern and Southeastern Europe as well as parts of the Maghreb and the Mashriq. (Read more about the history, culture and heritage of the largest and longest lasting Empire in history.)

Its defeat in the Russo-Turkish war of 1877-1878 demonstrates the Ottoman Empire's downfall in the late 19th century which progressively led to the creation of new nation-states in the European continent such as Bulgaria, Montenegro, Romania and Serbia. (Learn more about the Treaty of San Stefano that settled the Russo-Turkish conflict and accelerated the progressive independence of the former Ottoman Provinces.)

On the June 28, 1914, the heir to the Austro-Hungarian throne, Archduke Franz Ferdinand, was assassinated in Sarajevo, sparking World War I. (See the film footage of Archduke Franz Ferdinand's July 1914 funeral.)

You can find a series of useful articles here about the Great War from the BBC, ranging in topics from the descent into war, campaigns and battles, the human experience of the war and on the debates and controversies in the aftermath of WWI. You can also map out the main events of the war.

After the signing of the Armistice that effectively ended World War I on November 11, 1918, the Paris Peace Conference was organized to set new peace terms dealing with war reparations and establishing new borders. A series of separate treaties resulted that would change Europe's borders notably creating a Polish State. Among the many treaties resulting from this Conference, the Treaty of Versailles is the most famous.

Signed in June 1919, the Treaty of Versailles officially ended the war between Germany and the Allied Powers - including Great Britain, France and the USA. View Europe's borders in the interwar period and learn more about the Paris Peace Conference and the Treaty of Versailles that reshaped Europe in 1919.

Triggered by the German invasion of Poland on September 1, 1939, World War II would end in Europe on May 8, 1945 when Germany surrendered. Unlike World War I, World War II battlefields extended across the world. (See more here about how the War goes global, June 1941 - 1942). The battles were particularly fierce in Central and Eastern Europe. (Read more in this article). The term Holocaust has come to describe the murder of six million Jews in Europe orchestrated by the Nazis during World War II. The Final Solution (The Holocaust, The Shoah).

Following the end of World War II a new war began - the Cold War - which lasted for the next forty years. The Cold War can be described as the state of political conflict and military tensions between the Soviet Union along with its satellite states- the East and the United States and its allies - the West.

The Cold War is often represented by the concept of an "Iron Curtain." In March 1946, Winston Churchill coined the expression Iron Curtain to stress that Europe's ideological and physical boundaries were divided. The Iron Curtain turned into a reality with the construction of the Berlin wall in 1961 which remained standing until the collapse of the Soviet Union in 1991.

The Soviet Union has its roots in 1917 October Revolution. The revolt led by Vladimir Lenin ended with the Bolsheviks gaining power and led to the creation of the Soviet Union in 1922, that would last 70 years. After Lenin's death in 1924, Joseph Stalin came to power imposing a Terror Regime on the Soviet Union that would be pursued after his own death in 1953.

After the collapse of communism in Central Europe in 1989 many countries opened up museums, which deal with their communist pasts. Listed below are some of these museums which make it possible to visit them online:

The Global Museum on Communism is an international portal created to honor the more than 100 million victims of communist tyranny and educate future generations about past and present communist atrocities. The museum tells the story of communism, from discussing Karl Marx's The Communist Manifesto and the communist regimes in Central and Eastern Europe to today's brutal suppression of Tibet by communist China.

For almost half a century, Europe was forcibly divided into East and West by the "Iron Curtain", a political and ideological border stretching from the Barents Sea to the Black Sea. The European cycle track Iron Curtain Trail invites people to retrace and experience this important part of the continent's history.

The Berlin Wall

Read this BBC article about the fall of the Berlin wall and how Berliners celebrated this historic event. (Here is a video of this celebratory moment). Watch also on BBC News how Berlin remembered the fall of the wall 20 years later in 2009.